rcu: Move RCU-related source code to kernel/rcu directory

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 0 insertions, 341 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
deleted file mode 100644
index c07af1c4e1bb..000000000000
--- a/kernel/rcupdate.c
+++ /dev/null
@@ -1,341 +0,0 @@
-/*
- * Read-Copy Update mechanism for mutual exclusion
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright IBM Corporation, 2001
- *
- * Authors: Dipankar Sarma <dipankar@in.ibm.com>
- *	    Manfred Spraul <manfred@colorfullife.com>
- *
- * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
- * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
- * Papers:
- * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
- * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- *		http://lse.sourceforge.net/locking/rcupdate.html
- *
- */
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <linux/atomic.h>
-#include <linux/bitops.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/mutex.h>
-#include <linux/export.h>
-#include <linux/hardirq.h>
-#include <linux/delay.h>
-#include <linux/module.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/rcu.h>
-
-#include "rcu.h"
-
-module_param(rcu_expedited, int, 0);
-
-#ifdef CONFIG_PREEMPT_RCU
-
-/*
- * Preemptible RCU implementation for rcu_read_lock().
- * Just increment ->rcu_read_lock_nesting, shared state will be updated
- * if we block.
- */
-void __rcu_read_lock(void)
-{
-	current->rcu_read_lock_nesting++;
-	barrier();  /* critical section after entry code. */
-}
-EXPORT_SYMBOL_GPL(__rcu_read_lock);
-
-/*
- * Preemptible RCU implementation for rcu_read_unlock().
- * Decrement ->rcu_read_lock_nesting.  If the result is zero (outermost
- * rcu_read_unlock()) and ->rcu_read_unlock_special is non-zero, then
- * invoke rcu_read_unlock_special() to clean up after a context switch
- * in an RCU read-side critical section and other special cases.
- */
-void __rcu_read_unlock(void)
-{
-	struct task_struct *t = current;
-
-	if (t->rcu_read_lock_nesting != 1) {
-		--t->rcu_read_lock_nesting;
-	} else {
-		barrier();  /* critical section before exit code. */
-		t->rcu_read_lock_nesting = INT_MIN;
-#ifdef CONFIG_PROVE_RCU_DELAY
-		udelay(10); /* Make preemption more probable. */
-#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
-		barrier();  /* assign before ->rcu_read_unlock_special load */
-		if (unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
-			rcu_read_unlock_special(t);
-		barrier();  /* ->rcu_read_unlock_special load before assign */
-		t->rcu_read_lock_nesting = 0;
-	}
-#ifdef CONFIG_PROVE_LOCKING
-	{
-		int rrln = ACCESS_ONCE(t->rcu_read_lock_nesting);
-
-		WARN_ON_ONCE(rrln < 0 && rrln > INT_MIN / 2);
-	}
-#endif /* #ifdef CONFIG_PROVE_LOCKING */
-}
-EXPORT_SYMBOL_GPL(__rcu_read_unlock);
-
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
-EXPORT_SYMBOL_GPL(rcu_lock_map);
-
-static struct lock_class_key rcu_bh_lock_key;
-struct lockdep_map rcu_bh_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
-EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
-
-static struct lock_class_key rcu_sched_lock_key;
-struct lockdep_map rcu_sched_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
-EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
-
-int notrace debug_lockdep_rcu_enabled(void)
-{
-	return rcu_scheduler_active && debug_locks &&
-	       current->lockdep_recursion == 0;
-}
-EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
-
-/**
- * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
- *
- * Check for bottom half being disabled, which covers both the
- * CONFIG_PROVE_RCU and not cases.  Note that if someone uses
- * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
- * will show the situation.  This is useful for debug checks in functions
- * that require that they be called within an RCU read-side critical
- * section.
- *
- * Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
- *
- * Note that rcu_read_lock() is disallowed if the CPU is either idle or
- * offline from an RCU perspective, so check for those as well.
- */
-int rcu_read_lock_bh_held(void)
-{
-	if (!debug_lockdep_rcu_enabled())
-		return 1;
-	if (!rcu_is_watching())
-		return 0;
-	if (!rcu_lockdep_current_cpu_online())
-		return 0;
-	return in_softirq() || irqs_disabled();
-}
-EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
-
-#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
-
-struct rcu_synchronize {
-	struct rcu_head head;
-	struct completion completion;
-};
-
-/*
- * Awaken the corresponding synchronize_rcu() instance now that a
- * grace period has elapsed.
- */
-static void wakeme_after_rcu(struct rcu_head  *head)
-{
-	struct rcu_synchronize *rcu;
-
-	rcu = container_of(head, struct rcu_synchronize, head);
-	complete(&rcu->completion);
-}
-
-void wait_rcu_gp(call_rcu_func_t crf)
-{
-	struct rcu_synchronize rcu;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	crf(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
-}
-EXPORT_SYMBOL_GPL(wait_rcu_gp);
-
-#ifdef CONFIG_PROVE_RCU
-/*
- * wrapper function to avoid #include problems.
- */
-int rcu_my_thread_group_empty(void)
-{
-	return thread_group_empty(current);
-}
-EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
-#endif /* #ifdef CONFIG_PROVE_RCU */
-
-#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
-static inline void debug_init_rcu_head(struct rcu_head *head)
-{
-	debug_object_init(head, &rcuhead_debug_descr);
-}
-
-static inline void debug_rcu_head_free(struct rcu_head *head)
-{
-	debug_object_free(head, &rcuhead_debug_descr);
-}
-
-/*
- * fixup_activate is called when:
- * - an active object is activated
- * - an unknown object is activated (might be a statically initialized object)
- * Activation is performed internally by call_rcu().
- */
-static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
-{
-	struct rcu_head *head = addr;
-
-	switch (state) {
-
-	case ODEBUG_STATE_NOTAVAILABLE:
-		/*
-		 * This is not really a fixup. We just make sure that it is
-		 * tracked in the object tracker.
-		 */
-		debug_object_init(head, &rcuhead_debug_descr);
-		debug_object_activate(head, &rcuhead_debug_descr);
-		return 0;
-	default:
-		return 1;
-	}
-}
-
-/**
- * init_rcu_head_on_stack() - initialize on-stack rcu_head for debugobjects
- * @head: pointer to rcu_head structure to be initialized
- *
- * This function informs debugobjects of a new rcu_head structure that
- * has been allocated as an auto variable on the stack.  This function
- * is not required for rcu_head structures that are statically defined or
- * that are dynamically allocated on the heap.  This function has no
- * effect for !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
- */
-void init_rcu_head_on_stack(struct rcu_head *head)
-{
-	debug_object_init_on_stack(head, &rcuhead_debug_descr);
-}
-EXPORT_SYMBOL_GPL(init_rcu_head_on_stack);
-
-/**
- * destroy_rcu_head_on_stack() - destroy on-stack rcu_head for debugobjects
- * @head: pointer to rcu_head structure to be initialized
- *
- * This function informs debugobjects that an on-stack rcu_head structure
- * is about to go out of scope.  As with init_rcu_head_on_stack(), this
- * function is not required for rcu_head structures that are statically
- * defined or that are dynamically allocated on the heap.  Also as with
- * init_rcu_head_on_stack(), this function has no effect for
- * !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
- */
-void destroy_rcu_head_on_stack(struct rcu_head *head)
-{
-	debug_object_free(head, &rcuhead_debug_descr);
-}
-EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
-
-struct debug_obj_descr rcuhead_debug_descr = {
-	.name = "rcu_head",
-	.fixup_activate = rcuhead_fixup_activate,
-};
-EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
-#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-
-#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE)
-void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp,
-			       unsigned long secs,
-			       unsigned long c_old, unsigned long c)
-{
-	trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c);
-}
-EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
-#else
-#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
-	do { } while (0)
-#endif
-
-#ifdef CONFIG_RCU_STALL_COMMON
-
-#ifdef CONFIG_PROVE_RCU
-#define RCU_STALL_DELAY_DELTA	       (5 * HZ)
-#else
-#define RCU_STALL_DELAY_DELTA	       0
-#endif
-
-int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
-static int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;
-
-module_param(rcu_cpu_stall_suppress, int, 0644);
-module_param(rcu_cpu_stall_timeout, int, 0644);
-
-int rcu_jiffies_till_stall_check(void)
-{
-	int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout);
-
-	/*
-	 * Limit check must be consistent with the Kconfig limits
-	 * for CONFIG_RCU_CPU_STALL_TIMEOUT.
-	 */
-	if (till_stall_check < 3) {
-		ACCESS_ONCE(rcu_cpu_stall_timeout) = 3;
-		till_stall_check = 3;
-	} else if (till_stall_check > 300) {
-		ACCESS_ONCE(rcu_cpu_stall_timeout) = 300;
-		till_stall_check = 300;
-	}
-	return till_stall_check * HZ + RCU_STALL_DELAY_DELTA;
-}
-
-static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
-{
-	rcu_cpu_stall_suppress = 1;
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block rcu_panic_block = {
-	.notifier_call = rcu_panic,
-};
-
-static int __init check_cpu_stall_init(void)
-{
-	atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block);
-	return 0;
-}
-early_initcall(check_cpu_stall_init);
-
-#endif /* #ifdef CONFIG_RCU_STALL_COMMON */